Custom Component extending Well Component - not showing Drop Zone

[jprashant28]

I am trying to create a custom nested component - so that I can change the way the children component are rendered. So I started off by extending a Well Component since it has the simplest Edit Form. While I am able to drag my custom component onto the Form, I am unable to get a drop zone for it - and thus am unable to add children components to it (like buttons etc.).

What am I missing?